There are DIP Switches like in almost every normal PC XT so it is no problem to find config in google. You have 512 kb RAM so You can add 128 kb.

Dosdays has the switch settings for IBM XT.

https://www.dosdays.co.uk/topics/xt_dip_switches.php

Yours is clearly an aftermarket clone board, so their info will be of limited use.

I'd expect the switches on switch bank 1 to more or less match the dip block on your board though.

Thansk a lot for the answers

I didn't know DIPs were standard on the XT. I thought they were different on each board.

On another note, I know it comes with 512KB of RAM, but it's missing 128KB to fully max it out. What chips are missing? They can't be the same:KM41256AP* 12 - 256K x 8 DYNAMIC RAM FAST PAGE MODE

muon wrote on 2025-04-10, 10:40:

I didn't know DIPs were standard on the XT. I thought they were different on each board.

Now that you mention it..
The Commodore PC10 from 1985 has similar (same) DIP switch settings, too.
I've noticed first time when installing an VGA card and then an i8087.
Both upgrades required making changes on that DIP block.

muon wrote on 2025-04-10, 10:40:

On another note, I know it comes with 512KB of RAM, but it's missing 128KB to fully max it out. What chips are missing? They can't be the same:KM41256AP* 12 - 256K x 8 DYNAMIC RAM FAST PAGE MODE

Each of these chips is 32KB (256K x 1bit). I see 18 of them that don't add up to 512KB but to 576KB?

XT's use parity so 9 chips per bank or row. Need 18 - 4164's to complete to 640k...

wierd_w wrote on 2025-04-10, 10:29:

Dosdays has the switch settings for IBM XT. […]
Show full quote

Dosdays has the switch settings for IBM XT.

https://www.dosdays.co.uk/topics/xt_dip_switches.php

Yours is clearly an aftermarket clone board, so their info will be of limited use.

I'd expect the switches on switch bank 1 to more or less match the dip block on your board though.

And the jumpers, near the keyboard connector?

Just an FYI.

The turbo switch on your mainboard is only read upon cold boot or reset.
Changing the turbo mode using the switch while running is not implemented in the m1101 chipset.
Dependent on the BIOS & keyboard driver, a hotkey like ctrl-alt-numpad-minus or plus can be used and a software option is also possible.

I had no idea. Thanks so much for the information.

muon wrote on 2025-04-10, 10:40:

What chips are missing? They can't be the same:KM41256AP* 12 - 256K x 8 DYNAMIC RAM FAST PAGE MODE

The chips required for the upgrade to 640K are 64K*1 chips. You need 18 of them. As the first two banks have an access time of 120ns (-12 in the model number), the new chips should be as fast as them, so get -12 or -10 chips, but no -15 or -20 chips. Typically, 64K*1 (or 64K x 1) dynamic RAM chips have model numbers like 4164 or 4264. Avoid chips by Micron Technologies. While that company isn't generally bad, specifically their 64K*1 chips are known for failing more often than the competing chips.